The invention relates to an apparatus for handling flat coiler cans before, during and after filling the cans with sliver, such as cotton sliver or chemical fiber sliver, by a sliver producing textile machine such as a drawing frame. The flat cans have an elongated horizontal cross section. The sliver is discharged by a coiler head which rotates about a stationary axis and the sliver is deposited in coils while the coiler can which undergoes filling is reciprocated in its longitudinal direction. The apparatus further has a conveyor track between the charging position (sliver filling station) and an empty-can and full-can storing device. The can can be shifted back-and-forth in the sliver filling station and may be advanced to or removed from the sliver filling station on the conveyor track.
WO Publication No. 91/18135 discloses an apparatus in which an empty-can storing device and a full-can storing device are positioned in series. With the two can storing devices in each instance can displacing devices constituted by conveyor belts or chains are associated which are deflected immediately adjacent a further conveyor belt or a further conveyor chain by means of end rollers. The conveyor belt or conveyor chain extends from the can storing device to the vicinity of the coiler head of the drawing frame and is deflected by end rollers. The conveyor chain drives a carrier which engages a flat can and advances the same up to the zone of the coiler head where the flat can is taken over by two arms of a can shifting device which functions as a can-reciprocating apparatus. The arms can be swung back out of the zone of the flat can to ensure that the flat can may be brought by the conveyor belt into the can-reciprocating zone of the drawing frame and furthermore, the arms are movable toward one another to form a gripper to firmly clamp the flat can between themselves. The can-reciprocating apparatus is required because, as opposed to a sliver-deposition into coiler cans of circular cross section, the coiler head of the drawing frame cannot distribute the sliver in a uniform manner in a flat can. To ensure that the required can-reciprocating motion during the filling operation is not interfered with, the conveyor chain is returned from the reciprocating zone into the base position in which the can carrier is situated on that side of the can storing device which is oriented away from the drawing frame. An additional conveyor chain with a carrier is provided which is deflected by end rollers. The end rollers are so arranged that the carrier may be brought into the immediate vicinity of the coiler head from that side of the can storing device which is oriented away from the drawing frame to receive a flat can so that the flat can may then be taken over by the arms. The end rollers of the conveyor chain are so arranged that the flat can may be brought back into the can storing device by the carrier which is first situated on the side oriented away from the can storing device. The conveyor chains are, along a certain length portion, arranged parallel to one another whereby their effective range overlaps. The two conveyor chains together form a can shifting device to supply and to remove the flat cans. It is a disadvantage of such a prior art arrangement that it is complex both structurally and as a part of the system. It is a particular drawback that the can moving device is a two-part construction requiring two separate shifting devices for the flat cans. It is a further disadvantage that the separate shifting devices have to be separately driven and their control has to be designed with additional technological input and expense. Further, during operation, delays are caused by the switchover times from one shifting device to the other.